Hi,
On Mon, 2025-06-30 at 10:49 +0100, Dave Cridland wrote:
Can we structure the XML change such that a degradation into a single reply works? Perhaps the first reply is as XEP-0461, but subsequent replies are a different element (possibly can be the same namespace).
I think a multi-reply should not "degrade" into a single-reply with to only one of the messages, as this would mean that the explicitly intended meaning of replying to more than one message is lost entirely. Instead the most graceful fallback is probably to instead have a message that has 2 block-quotes to refer to the previous message (and have those tagged with fallback indicator so they are hidden if multi-reply is supported).
I'm possibly reading more into this statement than you intended, but in general we want to only bump the namespace where incompatibilities would otherwise arrive undetected. So no namespace bump unless we absolutely have to, but if we have to, we absolutely do it.
In this case a namespace bump is totally reasonable:
- We don't have a lot of implementations yet and the XEP is very young.
- Good fallbacks are possible for unsupporting clients
- Updated clients can temporarily send both versions at the same time for cases that would've been supported by the old spec (single message replies)
On Mon, 2025-06-30 at 13:43 +0000, Stephen Paul Weber wrote:
I don't see how that's a problem. Order is preserved in any case.
I believe this would be the first time we'd give meaning to the ordering of direct child elements of stanzas. Previously, those elements have been processed largely independent of each other.
Using a grouping element just opens us up to new fun cases like multiple
grouping elements.
Well, many existing XEPs don't allow for their elements to exist multiple times and not all make that really explicit. You likely can't (or shouldn't be able to) send multiple XEP-0353 <propose/> in a single message or have multiple XEP-0319 <idle/> in a presence. If you do, you end up in undefined behavior. Should we make more explicit what should happen in those cases? Yes, certainly. But them existing multiple times is really the only "fun case" you can come up with.
I like that the syntax matches more the semantics if you "group" them. The message is a reply to two messages, not a message that is two replies.
On Mon, 2025-06-30 at 13:45 +0000, Stephen Paul Weber wrote:
I'm interested to see a prototype of this rnd especially what kinds of UX
are possible for multiple replies but no quotes.
Until then I think any discussion of XEP changes or namespace bumps is a bit
cart before the horse.
As was mentioned by Greatsword in their initial message, there are already non-XMPP messengers that support this, it's really not something innovative. As this is not the first time this feature is desired, there seems to be people interested. For reference, here's screenshots of revolt.chat when doing replies to multiple messages:
https://imgur.com/a/6n1oiPd
Marvin